Validations of Particle/Fluid Interaction Models

2004 ◽  
Author(s):  
Z. Charlie Zheng ◽  
N. Zhang ◽  
S. Eckels
Keyword(s):  
Turbulence Model ◽  
Gravitational Force ◽  
Simulation Models ◽  
Fluid Simulation ◽  
Particle Collision ◽  
Type Model ◽  
Interaction Models ◽  
Fluid Interaction ◽  
Good Agreement

Several particle/fluid simulation models have been tested, including Euler-Lagrange type and Euler type models. Other effects, such as gravitational force, turbulence model and particle collision, are also discussed. Comparisons with literature data have shown good agreement by using the Euler type model.

Modeling of mass transfer in biofilms in oscillatory flow conditions using k-ɛ turbulence model

2003 ◽  
Vol 3 (1-2) ◽  
pp. 201-207
Author(s):  
H. Nagaoka ◽  
T. Nakano ◽  
D. Akimoto
Keyword(s):  
Numerical Simulation ◽  
Mass Transfer ◽  
Turbulence Model ◽  
Uptake Rate ◽  
Oscillatory Flow ◽  
Substrate Uptake ◽  
Flow Conditions ◽  
Mass Transfer Mechanism ◽  
Substrate Uptake Rate ◽  
Good Agreement

The objective of this research is to investigate mass transfer mechanism in biofilms under oscillatory flow conditions. Numerical simulation of turbulence near a biofilm was conducted using the low Reynold’s number k-ɛ turbulence model. Substrate transfer in biofilms under oscillatory flow conditions was assumed to be carried out by turbulent diffusion caused by fluid movement and substrate concentration profile in biofilm was calculated. An experiment was carried out to measure velocity profile near a biofilm under oscillatory flow conditions and the influence of the turbulence on substrate uptake rate by the biofilm was also measured. Measured turbulence was in good agreement with the calculated one and the influence of the turbulence on the substrate uptake rate was well explained by the simulation.

Numerical Simulation of Flow in a Horizontal Sedimentation Tank

2011 ◽  
Vol 130-134 ◽  
pp. 3624-3627
Author(s):  
W.L. Wei ◽  
Zhang Pei ◽  
Y.L. Liu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Secondary Flow ◽  
Mixture Model ◽  
Turbulence Model ◽  
Two Phase ◽  
Sedimentation Tank ◽  
Phase Mixture ◽  
Good Agreement

In this paper, we use two-phase mixture model and the Realizable k-ε turbulence model to numerically simulate the advection secondary flow in a sedimentation tank. The PISO algorithm is used to decouple velocity and pressure. The comparisons between the measured and computed data are in good agreement, which indicates that the model can fully simulate the flow field in a sedimentation tank.

Measurement and Numerical Simulation of the Velocity Profile in the Thin Film of an Impinging Water Jet

2021 ◽  
Vol 144 (3) ◽  
Author(s):  
Matthias Joppa ◽  
Mike Bermuske ◽  
Frank Rüdiger ◽  
Lars Büttner ◽  
Jochen Fröhlich ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Simulation Model ◽  
Process Optimization ◽  
Low Cost ◽  
Simulation Models ◽  
Fluid Simulation ◽  
Doppler Velocity ◽  
Measurement Technology ◽  
Mean Velocity ◽  
Validation Data

Abstract Impinging circular free-surface water jets are used in challenging cooling and cleaning tasks. In order to develop simulation models for process optimization, validation data are required, which are currently not available. Therefore, the flow field of these jets is studied for the first time with the novel laser Doppler velocity profile sensor. The mean velocity field and fluctuations are measured within the stagnation and adjacent redirection region for radial coordinates up to three times the nozzle diameter. In the examined parameter range with jet velocities up to 17 m/s and nozzle diameters up to 5.2 mm, i.e., Reynolds numbers up to 69 500, thin films of a few hundred micrometers are formed, which hinder the measurement with common optical measuring systems. Based on the measurement results, a comparatively low-cost volume of fluid simulation model is developed and validated that presumes a relaminarized film flow. The profiles measured and the simulated flow show very good agreement. In the future, the simulation model provides a basis for process optimization and the innovative measurement technology used will prospectively provide further detailed insights into other flows with high velocity gradients.

scholarly journals Design and analysis of flow rectifier of gas turbine flowmeter

2013 ◽  
Vol 17 (5) ◽  
pp. 1504-1507 ◽  
Author(s):  
Zhi-Fei Li ◽  
Zheng Du ◽  
Kai Zhang ◽  
Dong-Sheng Li ◽  
Zhong-Di Su ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Computational Model ◽  
Pressure Distribution ◽  
Gas Turbine ◽  
Turbulence Model ◽  
Pressure Loss ◽  
Three Dimensional ◽  
Turbine Flowmeter ◽  
Good Agreement

Three-dimensional computational model for a gas turbine flowmeter is proposed, and the finite volume based SIMPLEC method and k-? turbulence model are used to obtain the detailed information of flow field in turbine flowmeter, such as velocity and pressure distribution. Comparison between numerical results and experimental data reveals a good agreement. A rectifier with little pressure loss is optimally designed and validated numerically and experimentally.

3D Ice Accretion Simulation for Complex Configuration Basing on Improved Messinger Model

2014 ◽  
Vol 1025-1026 ◽  
pp. 148-155
Author(s):  
Cheng Xiang Zhu ◽  
Chun Ling Zhu ◽  
Bin Fu
Keyword(s):  
Numerical Methods ◽  
Flow Field ◽  
Turbulence Model ◽  
Calculated Result ◽  
Complex Configuration ◽  
Ice Accretion ◽  
Improved Method ◽  
Experiment Data ◽  
Distribution Scheme ◽  
Good Agreement

Ice accretion on 3D complex configuration is studied by numerical methods. The flow field is obtained by using Fluent 6.0 with a S-A turbulence model. Droplet trajectories and impingement characteristics are obtained by using the Eulerian approach. Ice shape is calculated based on the improved Messinger model with a new runback distribution scheme. By applying the method presented in this paper, ice accretion on NACA0012 is computed and the results are in good agreement with the available experiment data. It preliminarily shows that the improved method in this paper is feasible, Meanwhile, ice accretion on a four-element wing is studied. According to the analysis of the calculated result, the method presented in the paper can correctly simulate the ice accretion on 3D complex configuration.

Comparison and Validation of Dynamics Simulation Models for a Structurally Flexible Manipulator

1998 ◽  
Vol 120 (3) ◽  
pp. 404-409 ◽  
Author(s):  
Jeff Stanway ◽  
Inna Sharf ◽  
Chris Damaren
Keyword(s):  
Simulation Models ◽  
Element Model ◽  
Experimental Results ◽  
Dynamics Simulation ◽  
Flexible Manipulator ◽  
Direct Drive ◽  
Inertial Nonlinearities ◽  
Dynamics Models ◽  
The Finite Element Model ◽  
Good Agreement

This paper presents a series of experimental results obtained with a 2-DOF flexible-link direct-drive manipulator. First, we conduct a frequency analysis by comparing experimental natural frequencies with those predicted by the finite element model. Then, the time responses from four dynamics models are compared with each other and with the experiment. It is demonstrated that higher order nonlinearities are less important for slow maneuvers by close agreement between all four simulation models. For fast maneuvers, the two simpler models fail to predict a physically meaningful response. Good agreement with experimental results is attained with a model which accounts for all inertial nonlinearities. It is also shown that inclusion of damping in the dynamics models has a significant impact on their performance, as well as improving the correlation with experimental data.

scholarly journals Multi-fluid simulation models for inductively coupled plasma sources

2017 ◽  
Author(s):  
Madhusudhan Kundrapu ◽  
Seth A. Veitzer ◽  
Peter H. Stoltz ◽  
Kristian R. C. Beckwith ◽  
Jonathan Smith
Keyword(s):  
Inductively Coupled Plasma ◽  
Simulation Models ◽  
Fluid Simulation ◽  
Plasma Sources ◽  
Inductively Coupled

Study on Resistance Characteristics of Trilobal Throttling Element in Narrow Annular Channel

2017 ◽  
Author(s):  
Wu Youguang ◽  
Li Weihua ◽  
Jia Haijun
Keyword(s):  
Experimental Data ◽  
Turbulence Model ◽  
Annular Channel ◽  
Resistance Coefficient ◽  
Local Resistance ◽  
Function Change ◽  
Local Resistance Coefficient ◽  
Fluent Software ◽  
The Relationship ◽  
Good Agreement

An experimental study was performed to investigate the resistance characteristics of the trilobal throttling element in narrow annular channel, while corresponding flow fields analyzed using Fluent software with RNG k-ε turbulence model based on the structural grid for the trilobal throttling element with different placket angle. A relationship between the packet angle θ and the local resistance coefficient ξ is obtained. Results show that the local resistance coefficient obtained by numerical simulation of the trilobal throttling element in narrow annular channel have a good agreement with the experimental data, and their relative error is less than 8%. This also fully proves that the RNG k-ε turbulence model is suitable for the simulation of the trilobal throttling element in the narrow annular channel. The local resistance coefficient of the trilobal throttling element in narrow annular channel increases with rising packet angle θ, and the relationship is similar to the power function change.

scholarly journals Bus Impact on the Inductance Distribution of Electromagnetic Launchers

2021 ◽  
Author(s):  
Nail Tosun ◽  
Ozan Keysan
Keyword(s):  
Simulation Models ◽  
Careful Examination ◽  
Physical Conditions ◽  
Electromagnetic Launchers ◽  
Electromagnetic Launcher ◽  
Bus Structure ◽  
Electromagnetic Calculations ◽  
Operation Risk ◽  
Current Transients ◽  
Good Agreement

<div>Simulations are crucial in the electromagnetic launcher (EML) researches on account of extreme physical conditions. More energy into the system adds weight to the model’s accuracy as the operation risk rises. In this paper, the electromagnetic impact of the bus structure is discovered in a recently developed EMFY-3 electromagnetic launcher, is presented. An H-shaped bus structure is used for current injection. However, experiments showed that the H-shaped bus changes inductance calculations. A careful examination is made to reveal the physical reasoning of the bus impact. We hypothesize that the rail portion surrounded with bus geometry has less inductance than the rest due to the eddy current created by rail current transients, which should be calculated carefully through numerical calculations, i.e., 3-D Finite Element Method (FEM). Two different simulation models were constructed to test the hypothesis. Moreover, rail currents, breech, and muzzle voltages are measured to investigate electromagnetic calculations. Results showed a good agreement with experiments where the bus structure was modeled explicitly. That aspect showed that the bus structure should be well-examined when multiple PPS are connected.</div>

scholarly journals Second Quantization Approach to COVID-19 Epidemic

2021 ◽  
pp. 1-12
Author(s):  
Leonardo Mondaini ◽  
Bernhard Meirose ◽  
Felipe Mondaini
Keyword(s):  
South Korea ◽  
Time Evolution ◽  
Infection Rate ◽  
Theoretical Language ◽  
Time Dependent ◽  
Type Model ◽  
Second Quantization ◽  
The Mean ◽  
Stochastic Sir ◽  
Good Agreement

In this article, a stochastic SIR-type model for COVID-19 epidemic is built using the standard field theoretical language based on creation and annihilation operators. From the model, we derive the time evolution of the mean number of infectious (active cases) and deceased individuals. In order to capture the effects of lockdown and social distancing, we use a time-dependent infection rate. The results are in good agreement with the data for three different waves of epidemic activity in South Korea.

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